Tenderness and Chemical Composition of Elk (Cervus elaphus) Meat: Effects of Muscle Type, Marinade Composition, and Cooking Method

Effects of sodium tripolyphosphate (STPP; 0.1, 0.2, or 0.3%) and 0.5%NaCl on the color, cooking yield, and tenderness of moisture‐enhanced elk longissimus lumborum (LL) and semimembranosus (SM) muscles were assessed. Injected samples had significantly (P < 0.05) lower L, a, and b values and significantly (P < 0.05) higher cooking yields and lower shear force values compared to controls; shear force values did not differ among marination treatments. The amino acid composition of elk meat was typical for those of red meat species. Elk meat was very lean and had a relatively high ratio of polyunsaturated to saturated fatty acids. The present study found that addition of 0.5% NaCl with 0.2% or 0.3% STPP to the marinade was best at improving the cooking yield and tenderness of the resultant products.     

Production of Restructured Meat using Microbial Transglutaminase without Salt or Cooking

To produce restructured meat, microbial transglutaminase (MTGase) was evaluated for its ability to introduce covalent crosslinks between protein molecules. Pork muscle cubes were mixed with MTGase and held at 5°C for 2 hr for the enzyme reaction. Restructured products were analyzed for binding strength without cooking. MTGase treatment resulted in effective binding of meat pieces provided there was addition of salt (NaCl). To ensure proper binding without NaCl, some food proteins with MTGase were also investigated. Meat cubes in combination with MTGase and sodium caseinate showed acceptable bind, and sodium caseinate appeared to be a superior substrate for the crosslinking to meat proteins than soy protein, whey protein, or gelatin. These results suggest a useful method for producing restructured meat which can be distributed in the raw, chilled state.     

Sodium hydroxide and sodium tripolyphosphate effects on bind strength and sensory characteristics of restructured beef rolls

Restructured beef rolls formulated with 1% NaCl (controls) or with 1% NaCl plus 0.07% NaOH or 0.375% sodium tripolyphosphate (STPP) had different (p < 0.05) relative bind strength and cooked yield, as follows: STPP > NaOH > controls. Percent cooked yield was inversely affected (p < 0.05) by added water level (5 > 10 > 20%). Bind values were lower (p < 0.05) in rolls with 20% added water. NaOH and STPP rolls had higher pH (p < 0.05) than controls (6.28, 6.22, and 6.07, respectively). Panel cohesiveness, juiciness, and acceptability scores were also generally higher (p < 0.05) for NaOH and STPP rolls, compared to controls. There was a high correlation (0.93) between panel cohesiveness scores and instrumental bind values. At 20% added water, STPP rolls were preferred, but at 10% added water, STPP and NaOH rolls were similar in overall acceptability. Thus, if added water level is not too high, NaOH alone or perhaps with other binding agents may be an alternative to phosphates in cooked beef rolls.     

Myofibrillar Protein Solubility of Model Beef Batters as Affected by Low Levels of Calcium, Magnesium and Zinc Chloride

Preblended composites of semimembranosus and adductor muscles were stored 12h at 4°C with 2.0% NaCl, 0 or 0.05% CaCl₂, MgCl₂, or ZnCl₂ and 0 or 0.4% sodium tripolyphosphate (STPP). Model systems were formulated to contain 30% fat (high fat; HF) or 10% fat (low fat; LF). Divalent salts lowered extract pH and ZnCl₂ elicited the greatest reduction. At both fat levels, CaCl₂ increased and ZnCl₂ decreased protein solubility, compared to the control (p<0.05). Myosin was not detected in ZnCl₂-treated HF and LF batters without STPP and in the presence of STPP, MgCl₂ and ZnCl₂ increased myosin concentration at both fat levels (p<0.05). Zinc chloride increased actin concentration in HF batters; whereas, MgCl₂ decreased soluble actin in LF batters (p<0.05). Magnesium chloride (0.05%) increased soluble proteins in LF batters containing 0.4% STPP by increasing myosin extractability.     

Influence of Sodium Tripolyphosphate and Sodium Chloride on Moisture-Retention and Textural Characteristics of Chicken Breast Meat Patties

Chicken patties containing various levels of sodium tripolyphosphate (STPP) and NaCl were tested for moisture retention characteristics and instrumentally texture profiled. Both additives tended to increase moisture retention. Both additives also affected the textural quality of the patties. In the absence of NaCl, the STPP increased the product cohesiveness, springiness and chewiness at the highest phosphate level; but, in the presence of NaCI, the phosphate tended to increase these textural attributes, especially cohesiveness and chewiness, at lower phosphate levels. Improved meat quality might be achievable through a better understanding of relationships between NaCI, STPP, moisture retention and texture of poultry meat products.     

Effect of marinating ingredients on temperature-induced denaturation of hemoglobin and its relation to red blood spot formation in cooked chicken breast

Red blood spot (RBS) commonly found in cooked chicken breast has caused severe economic loss as it is perceived as a sign of undercooked product. The objectives of this study were to investigate the cause of RBS as related to common ingredients used in marination, based on both chicken breast and isolated chicken hemoglobin (Hb) models. The effect of sodium chloride (NaCl), sodium tripolyphosphate (STPP), and glucose on thermal denaturation of Hb was investigated along with the extent of RBS formation in cooked marinated chicken breast. After vacuum tumbling for 65 min and subsequent storage at 4 °C for 20 hr, STPP and glucose were not absorbed into the center of chicken breast. However, Na⁺ was absorbed after 12 hr storage. The denaturation temperature (T_d) of isolated chicken Hb decreased to 65.8 °C in the presence of 1.5 M NaCl, while that of the control was 69.4 °C. STPP at pH 9 decreased T_d of Hb to 61.4 °C. The alkaline pH induced by STPP destabilized the Hb structure. RBSs were observed at 100% incidence when cooked to core temperatures of 50 and 70 °C for 1 min. RBSs were completely eliminated at core temperature of 85 °C. The ingredients used during marination appeared to have a minimal effect on RBS formation due to their limited absorption into the chicken breast. The cooking temperature is a major factor governing RBSs, as it directly affects the denaturation of Hb.     

Effects of Collagen and Alkaline Phosphate on Time of Chopping, Emulsion Stability and Protein Solubility of Fine-Cut Meat Systems

Four meat emulsions were prepared with two levels of collagen and alkaline phosphate. Samples were taken at five different chopping temperatures and evaluated for total chopping time, emulsion stability and protein solubility. Adding additional collagen to meat emulsions shortened total chopping time, and decreased emulsion stability but had no effect on protein solubility. The addition of 0.25% sodium tripolyphosphate (STPP) improved emulsion stability but resulted in no significant (p>0.05) change in chopping time or protein solubility. The high-collagen-phosphate (HCP) treatment resulted in less fat, gelliquid, solid and total cookout when compared with high-collagen no-phosphate (HC) and low-collagen no- phosphate (LC) treatments. Maximum emulsion stability was obtained at 13°C.     

Temperature and NaCl Affect Growth and Survival of Escherichia coli 0157:H7 in Poultry-Based and Laboratory Media

In tryptic soy broth (TSB) and a poultry extract broth (PB) with 0 to 10% (w/v) NaCl incubated at 37°C, growth of E. coli 0157:H7 was inhibited at 28% NaCl whereas at 10°C, growth was inhibited at 24% NaCl in TSB and at 26% NaCl in PB. The bacterium did not grow at 4°C. Increased NaCl-sensitivity observed at 10°C was a bacteriostatic effect that was ineffective with increasing incubation temperature. At 10°C, E. coli 0157:H7 was more salt-tolerant in PB than in TSB, although PB growth rates were lower. Findings suggest that PB may be a more suitable medium for testing E. coli 0157:H7 in poultry products. Cells of E. coli 0157:H7 that were exposed to refrigeration (4°C) and/or NaCl for 24 days did not grow on MacConkey agar with 1% sorbitol.     

Walnut, microbial transglutaminase and chilling storage time effects on salt-free beef batter characteristics

Response surface methodology (RSM) was used to assess the effect of walnut content (W), microbial transglutaminase/sodium caseinate (MTG/C) content and storage time (ST) at 3 °C on water- and fat-binding properties, texture profile analysis and dynamic rheological characteristics of salt-free beef batters. Walnut addition favoured the binding properties and elastic modulus (G′) of raw meat batters (20 °C); however, increasing amounts of walnut caused G′ to decrease at 70 °C. MTG/C had no effect on binding properties, but it did cause increases in the hardness of cooked meat batters and in the rheological properties of both raw and cooked samples. The products formulated with MTG/C and stored for up to 11 days at 3 °C presented good gel-forming ability; however, binding properties were poor, so that other ingredients like walnut were needed to improve the binding properties of the products.     

Desorption isotherms of salted minced pork using K-lactate as a substitute for NaCl

The aim of this study was to obtain and compare water desorption isotherms of ground meat containing NaCl (0.107 kg NaCl/kg raw-meat dry matter) and/or K-lactate as NaCl substitute at two different levels of molar substitution (30% and 100%). A thin layer of salted ground meat was dried and sampled at pre-determined times. The moisture content of the samples and their water activities (a_w) were measured at 5 °C and 25 °C. Results showed that ground meat with NaCl and/or different K-lactate contents had a similar water desorption isotherm for a_w ranging from 0.7 to 1.0. Below 0.7, the water equilibrium content fell with small decreases in a_w faster for meat with NaCl than for meat with K-lactate. K-lactate could reduce the excessive hardening at the surface of salted meat products. Experimental desorption isotherms were compared to those estimated using two approaches of the Ross equation. Models provided a good fit for the experimental data.     

Frankfurters with Lean Finely Textured Tissue as Affected by Ingredients

Increasing salt concentration from 1.5 to 2.5% increased the emulsion stability of frankfurters made with lean finely textured tissue (LFTT). Sodium tripolyphosphate (STPP) at 0.25% improved stability and texture as well as processing and consumer cooking yields. Kappa (K)-carra-geenan (0.5%) reduced cooking losses and increased firmness. Isolated soy protein (ISP) at 2% also improved product stability and firmness but lowered sensory scores. The effect of ISP on sensory scores was greater for those frankfurters produced from lean finely textured beef than for those with lean finely textured pork. Increasing NaCl concentration or including STPP and K-carrageenan may improve comminuted meat products which contain 50% LFTT substituted for lean meat.     

Effect of Salt Reduction on Growth of Listeria monocytogenes in Meat and Poultry Systems

Abstract: Reducing sodium in food could have an effect on food safety. The objective was to determine differences in growth of Listeria monocytogenes in meat and poultry systems with salt substitutes. For phase 1, fresh ground beef, pork, and turkey with NaCl, KCl, CaCl₂, MgCl₂, sea salt, or replacement salt added at 2.0% were inoculated with L. monocytogenes to determine growth/survival during 5 d at 4 °C to simulate a pre‐blend process. L. monocytogenes populations significantly decreased (0.41 log CFU/g) during the storage time in beef, but no differences (P > 0.05) were observed over time in pork or turkey. Salt type did not affect (P > 0.05) L. monocytogenes populations during pre‐blend storage. MgCl₂ and NaCl allowed significant growth of aerobic populations during storage. For phase 2, emulsified beef and pork products were processed with 2% NaCl, KCl, sea salt, or a NaCl/KCl blend and post‐process surface‐inoculated with L. monocytogenes to determine growth/survival at 4 °C for 28 d. Pork products showed significantly greater L. monocytogenes population growth at all sampling times (0, 7, 14, 21, and 28 d) than beef products, but salt type had no effect on L. monocytogenes populations with sampling times pooled for data analysis. Although salt types had no impact on L. monocytogenes populations in preblend and emulsified meat products, pork and turkey preblends and emulsified pork had greater L. monocytogenes populations compared with beef products. These studies demonstrate that sodium may not affect the safety of preblends and emulsified meat and poultry products. Practical Application: odium reduction in food is an important topic because of sodium's unfavorable health effects. This research shows that reducing sodium in pre‐blends and emulsified meat and poultry products would have no effect on Listeria monocytogenes populations, but replacement of NaCl with MgCl₂ may affect growth of aerobic populations.     

Evaluation of Brining Ingredients and Antimicrobials for Effects on Thermal Destruction of Escherichia coli O157:H7 in a Meat Model System

ABSTRACT: Escherichia coli O157:H7 may become internalized during brine injection of meat. This study evaluated the effect of brining ingredients on E. coli O157:H7 in a meat model system after simulated brining, storage, and cooking. Fresh knuckles (5.3 ± 2.4% fat) or beef shoulder (15.3 ± 2.2% fat) were ground individually, mixed with an 8-strain composite of rifampicin-resistant E. coli O157:H7 (7 log CFU/g) and brining solutions. Treatments included no brining, distilled water, sodium chloride (NaCl, 0.5%), sodium tripolyphosphate (STP, 0.25%), sodium pyrophosphate (SPP, 0.25%), NaCl + STP, NaCl + SPP, NaCl + STP + potassium lactate (PL, 2%), NaCl + STP + sodium diacetate (SD, 0.15%), NaCl + STP + PL + SD, NaCl + STP + lactic acid (0.3%), NaCl + STP + acetic acid (0.3%), NaCl + STP + citric acid (0.3%), NaCl + STP + EDTA (20 mM) + nisin (0.0015%) or pediocin (1000 AU/g), NaCl + STP + sodium metasilicate (0.2%), NaCl + STP + cetylpyridinium chloride (CPC; 0.5%), and NaCl + STP + hops beta acids (0.00055%). Samples (30 g) were analyzed for pH, and total microbial and rifampicin-resistant E. coli O157:H7 (inoculum) populations immediately after mixing, storage (24 h at 4 °C), and cooking to 65 °C. Fat and moisture contents and water activity were measured after storage and cooking only; cooking losses also were determined. The effect of beef type on microbial counts, pH, and water activity was negligible. No reductions in microbial counts were obtained by the brining solutions immediately or after storage, except for samples treated with CPC, which reduced (P < 0.05) pathogen counts after storage by approximately 1 log cycle. Cooking reduced pathogen counts by 1.5 to 2.5 logs, while CPC-treated samples had the lowest (P < 0.05) counts compared to any other treatment. These data may be useful in developing/improving brining recipes for control of E. coli O157:H7 in moisture-enhanced beef products.     

Interaction of Reduced NaCl, Sodium Acid Pyrophosphate and pH on the Antimicrobial Activity of Comminuted Meat Products

Meat (beef-pork) batters were formulated with NaCl (2.3% and 4.1% brine) and with 0.5% sodium acid pyrophosphate (SAPP) in combination with 2.3% brine. The adjusted pH of raw batters resulted in cooked meat pH values of 5.7, 6.0, and 6.3. Inoculated (Clostridium sporogenes spores) and uninoculated batters in cans were cooked to 70°C and stored for abuse at 27°C. Microbial growth was delayed and the short shelf-life of low brine (2.3%) products was extended with SAPP in the formulation. The antimicrobial properties of treatments with SAPP were due to both declining pH and presence of phosphate in the formulation. Potential mechanisms of microbial inhibition by SAPP are discussed.     

Low‐salt restructured fish products using microbial transglutaminase as binding agent

Low‐salt restructured silver carp products were obtained using mechanically deboned fish meat from filleting wastes of silver carp (Hypophthalmichthys molitrix). The additives used were NaCl at three levels (0 (control), 10 and 20 g kg^?1) and microbial transglutaminase (MTGase) also at three levels (0 (control), 3 and 6 g kg^?1). The fish meat was massaged with the additives at <15 °C for 1 h. The massaged fish paste was then packed into steel stainless tubes and cooked at 40 °C for 30 min followed by 90 °C for 15 min. Changes in mechanical properties (texture profile analysis and punch test), solubility, electrophoretic profile and expressible water were evaluated. Hardness was in the range from 26.3 to 52.4 N, cohesiveness varied from 0.185 to 0.318 and springiness varied from 0.418 to 0.768. Increasing the amount of both additives improved the mechanical and functional properties of the restructured silver carp products. MTGase activity was associated with a decrease in protein solubility and a decrease in the myosin band (SDS‐PAGE). Increasing NaCl decreased the amount of expressible water. The results indicated that it is feasible to obtain low‐salt restructured silver carp products with improved mechanical and good functional properties using 3 g kg^?1 MTGase and 10 g kg^?1 NaCl. © 2002 Society of Chemical Industry     

Inhibition of Clostridium sporogenes PA 3679 and Natural Bacterial Flora of Cooked Vacuum-Packaged Bratwurst by Sodium Acid Pyrophosphate and Sodium Tripolyphosphate With or Without Added Sodium Nitrite

Survival and growth of inoculated Clostridium sporogenes PA3679 and natural aerobic and anaerobic bacterial flora were studied in refrigerated (5°C) and subsequently temperature abused (24–25°C), cooked, vacuum-packaged bratwurst containing 0.5% sodium acid pyrophosphate (SAPP) or sodium tripolyphosphate (STPP) with or without sodium nitrite. Phosphates alone or combined with nitrite did not affect aerobic bacterial counts but resulted in reduced clostridial and anaerobic counts at 5°C. Upon temperature abuse, inhibition of all bacteria by SAPP was significant (P<0.05) for up to 48 hr and greatly enhanced by 100 ppm but not by 50 ppm sodium nitrite, whereas STPP lost its antimicrobial properties after 24 hr. Soluble orthophosphate levels had a positive correlation with bacterial inhibition in SAPP-treated bratwurst.     

Protein Oxidation at Different Salt Concentrations Affects the Cross‐Linking and Gelation of Pork Myofibrillar Protein Catalyzed by Microbial Transglutaminase

In a fabricated then restructured meat product, protein gelation plays an essential role in producing desirable binding and fat‐immobilization properties. In the present study, myofibrillar protein (MFP) suspended in 0.15, 0.45, and 0.6 M NaCl was subjected to hydroxyl radical stress for 2 or 24 h and then treated with microbial transglutaminase (MTGase) in 0.6 M NaCl (E : S = 1 : 20) at 4 and 15 °C for 2 h. Protein cross‐linking and dynamic rheological tests were performed to assess the efficacy of MTGase for mediating the gelation of oxidized MFP. MTGase treatments affected more remarkable polymerization of myosin in oxidized MFP than in nonoxidized, especially for samples oxidized at 0.6 M NaCl. Notably, the extent of MTGase‐induced myosin cross‐linking at 15 °C in oxidized MFP improved up to 46.8%, compared to 31.6% in nonoxidized MFP. MTGase treatment at 4 °C for MFP oxidized in 0.6 M NaCl, but not MFP oxidized in 0.15 M NaCl, produced stronger gels than nonoxidized MFP (P < 0.05). The final (75 °C) storage modulus (G′) of oxidized MFP gels was significantly greater than that of nonoxidized, although the G′ of the transient peak (～44.5 °C) showed the opposite trend. Overall, oxidation at high salt concentrations significantly improved MTGase‐mediated myosin cross‐linking and MFP gelation. This might be because under this condition, MTGase had an increased accessibility to glutamine and lysine residues to effectively initiate protein–protein interactions and gel network formation.     

Antimicrobial Activity and Functionality of Reduced Sodium Chloride and Potassium Sorbate in Uncured Poultry Products

Uncured turkey and chicken breast meat products, formulated with NaCl (0.65 and 1.30%) and potassium sorbate (0 and 0.26%), were tested for antimicrobial activity and functional properties. The chopped products were inoculated (Clostridium sporogenes, 10/g) in cans and in packages and abused at 20°C. Microbial growth and gas production were rapid at both NaCl levels tested. Inclusion of potassium sorbate in the formulation delayed initiation and rate of microbial growth and gas production. Potassium sorbate also reduced (P<0.05) weight losses during cooking of the low NaCl turkey product. Rates of gas production were similar in canned and vacuum packaged products. Differences in microbial growth and gas production between chicken and turkey products were minor.     

Water Binding Ability of Meat Products: Effect of Fat Level, Effective Salt Concentration and Cooking Temperature

This study investigated the effect of fat level (5 and 30%), effective salt (NaCl) concentration (1.33–3.73%) and cooking temperature (56–80°C) on water binding ability (WBA) of a finely comminuted meat product. When compared at the same effective salt concentration, fat level had little effect on WBA. The effective salt concentration determined the maximum temperature product could be heated to before WBA started to decrease: these temperature ranged from 57°C at the lowest salt concentration to 68°C at the highest. Salt level also determined rate at which WBA decreased with increasing temperature: rates ranged from – 1.3% per °C at the lowest salt concentration to – 0.3% per °C at the highest. Increasing effective salt concentration above 2.93% had no beneficial effect on WBA.     

Effect of sodium phytate, sodium pyrophosphate and sodium tripolyphosphate on physico-chemical characteristics of restructured beef

The effects of 0.5% sodium phytate (SPT), sodium pyrophosphate (SPP), and sodium tripolyphosphate (STPP), along with 1% NaCl, on physico-chemical properties of restructured raw and cooked beef were evaluated. In raw beef stored for 1 day at 4 ° C, the SPT, SPP, and STPP increased pH and salt-soluble protein level and decreased %MetMb and thiobarbituric acid reactive substances (TBARS), compared to the control with salt alone (p < 0.05). In cooked beef, SPT, SPP, and STPP increased bind strength, cook yield, moisture level, and pH, and decreased TBARS (p < 0.05). SPP and STPP increased orthophosphate in both raw and cooked beef (p < 0.05), compared to the SPT and control. SPT, SPP, and STPP decreased the Hunter color L and b values and increased a value in raw beef (p < 0.05) but had no effect on the Hunter color values in cooked beef. The binding value of SPP and STPP were similar over time, and the time to reach maximum binding strength was 10s longer than SPT and 25s longer than the control. These results indicate that SPT compares favorably with traditional phosphates for bind strength and cooked yield, but SPT was slightly more effective than other phosphates for reduction of TBARS 1 day after cooking.